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How suitable is apple orchard netting as a sunburn control measure?

Written by Antoinette Avorgbedor, Intern at Washington State University’s Tree Fruit Research and Extension Center and the Center for Sustaining Agriculture and Natural Resources

More likely than not, you have passed large apple orchards in your travels around the Pacific Northwest area and observed nets spanning wide areas of apple trees. Sometimes the entire top and all the sides of orchards are enclosed. A 2017 survey conducted in Washington State to assess the extent of netting found that about 5% of the surveyed acres were under nets and an additional 7% was estimated to be added in 2018 (Mupambi et al. 2019). Intuitively, you think nets are supposed to keep pests and trespassers out. At least, that is what I thought when I first saw an apple orchard covered with netting. That happens to be only a secondary reason for which tree fruit growers invest in such extensive enclosing techniques. A whopping 98.3% of the growers surveyed indicated that sunburn reduction was one of their most important reasons for using netting (the survey allowed growers to choose multiple reasons). I couldn’t help but wonder: What does this growing popularity of shade netting mean for the future of apple sunburn control?

Sunburn in Granny Smith apples. Photos: I. Hanrahan and M. Mendoza. Reproduced with permission, from Mupambi et al. 2019.

I’m working as an intern with Lee Kalcsits, Washington State University tree fruit physiologist. Dr. Kalcsits and his team have been extensively researching the impacts of netting on apple orchards. Their results indicate that the sunlight scattered by netting provides a more conducive environment for plant and fruit development than harsh, direct sunlight. In addition, leaf and fruit surface temperature, as well as soil temperatures, are lowered by netting. Water loss by evapotranspiration is also reduced when nets are used in orchards.

One might ask: how relevant is this information? From my perspective, these findings are potentially revolutionary to the improvement of sustainable water use for agriculture and the overall maximization of tree fruit production quality. Many apple growers spray water from overhead sprinklers to cool down fruit in the hotter months of summer, a practice known as evaporative cooling. Considering that an estimated 179,146 acres of apples were grown in Washington State in 2017 and an average 32,317 liters (0.026 ac-ft) were used for irrigation per acre daily, let’s do some grade school math. How much water was used in 2017 to reduce sunburn in Washington State if evaporative cooling consumed about 36% of the irrigation water? That’s right! A whole lot of water used annually! Of course, that is a very rough estimate, but there is ongoing research to accurately measure and quantify the amount of water expended during the season on evaporative cooling.

Water is an essential yet increasingly scarce resource globally, especially for agriculture. Efforts to conserve water in the Columbia River Basin could play a pivotal part in maintaining the longevity and productivity of the massive fruit growing industry in the Pacific Northwest. One can acknowledge the potential to substitute the extensive use of water in evaporative cooling with netting, although the amount of water saved has not yet been quantified. Moreover, there is a potential to substantially reduce irrigation volume and/or frequency, because netting reduces tree and soil water loss by evapotranspiration. “Netting”, Kalcsits says, “is a viable solution to replace the use of evaporative cooling to prevent sunburn in high-light apple-growing regions such as the Pacific Northwest.  It has added benefits of fruit protection from hail, wind, and enhanced growth and productivity.”

The additional benefits of netting are bonuses for some, but not all, scales of orchards. Retrofitting nets in an orchard is also an expensive investment with labor-intensive installation processes. The use of polyethylene materials comes at a cost to the environment; we need to think about how to dispose of voluminous amounts of netting material after their useful life ends. But bearing in mind that orchard netting can last ten or more years if proper care is taken, a cost-benefit analysis may reveal economic benefits overall.

Small apple trees with blue, white and red netting above
Red, blue and pearl colored netting in an apple orchard provide variety for apple producers to choose from. Photo: G. Mupambi.

Then again, such extrapolations are very dependent on individual growers’ needs and each case may vary vastly. Luckily, the technology of netting presents variety as well. The bottom line: there are various methods of netting structure installations, different net colors and shading percentages that provide a wide array of possibilities for different categories of apple growers to decide what works best for their type of orchards.

As temperatures rise in the future and the timing of available water shifts, fruit growers may experience an increasing need to conserve water for irrigation purposes. Netting could then become a desirable, if not absolutely necessary, method of reducing tree fruit loss due to sunburn, together with wind and hail damage. Further studies are being undertaken by Dr. Kalcsits and his team to quantify the water-savings potential of employing netting compared to evaporative cooling. Also, more researchers will be working to bridge the information gaps that currently exist with regards to the economic benefits. My hope, in the meantime, is that the advancement of netting in the apple growing industry can be a means to conserve our water and improve agriculture in the region.

 

Reference:

Mupambi, G., Layne, D.R., Kalcsits, L.A., Musacchi, S., Serra, S., Schmidt, T., Hanrahan, I., 2019. Use of Protective Netting in Washington State Apple Production. Washington State University Extension Publication No. TB60E, 1–20.

 

Also published at AgClimate.net

Soil (health) evaluation begins by asking “What’s the problem with my soil?”

Clod of soil showing fine roots
When evaluating your soil, start with the problems. Photo: A. McGuire.

Soil health – the pursuit that launched a thousand soil tests. I have not actually counted them, but many people are working on many ways to evaluate soil health. Some are looking at indicators of soil biology status, others at the soil’s physical state, many at various measurements of soil organic matter. There are lists of tiers of tests: the USDA’s Natural Resource Conservation Service has a list, the Soil Health Institute has a list, with tiers, and the soils lab at Oregon State University has a list. The lists are similar, but not identical. Commercial labs are joining the effort offering various tests: Solvia, the Haney test, fungal:bacterial ratios, and more. The lists will get pared down and labs will figure out the most relevant tests for their clientele, but before you take any soil samples, before you have any samples analyzed, before you start worrying about your soil biology, ask yourself, “what’s the problem with my soil?”

The problem with lab-based soil health evaluation is that it is not focused on one problem, on your problem. Often it is assumed that you don’t have soil health and that you need to get it, but the lack of soil health is not a real problem. Nor is your problem low active carbon, soil respiration, or microbial biomass. Those soil health indicators may or may not correlate with the actual problems you have with your soil…if you have a problem. And that is the place to start, determining if you have a real problem with your soil, and if you do, what exactly is it? Start by asking: what is your soil doing that you don’t want it to do, or what should it be doing that it’s not?

Problem-based soil evaluation

Here is a series of questions to start your problem-based soil evaluation.  Originally from Caley Gasch, soil scientist with North Dakota State University, I have modified them a bit, putting the problems in order from higher to lower in terms of the problem’s long-term consequences, harmful effects, and responsiveness to management.

Is your soil healthy? Does it blow or flow away? Does it allow water to soak in quickly? Does it drain? Does it crust? Does your crop recover most of the nutrients you apply? Are there areas where plants die or grow poorly?

What we want is for the soil to function in a way that enhances the main goal of agriculture: to produce food, and to keep on producing food. Function here has to do with air, water, and nutrients.

Erosion is first. If you have erosion, water or wind, fix it first. It makes no sense to be worried about soil biology, mycorrhizae, soil regeneration, or the soil food web if your soil is leaving your farm. The good news is that many of the fixes for soil erosion – increased residues on the soil surface, reduced tillage, cover crops – also benefit other aspects of soil health.

Next is how your soil handles water at the surface, infiltration, and below the surface, drainage. Then surface crusting, nutrient cycling and finally soilborne pests and diseases.

If you go down the list and your answer to the last question is “yes” then you must determine the most likely reason for your crop’s problems. This is where a shovel can help and if needed, a diagnostic lab. Is it soilborne disease, insects, salinity, etc.?

This list covers the most common problems but not all of them. Some of the problems may be related to each other. If they are, determine what they have in common. For instance, poor infiltration and wind erosion may be related to the lack of soil structure which is related to the low amount of soil organic matter. Why is there low soil organic matter? Low residue crops, too much tillage, plowing the surface organic matter into deeper layers? Keep asking why until you come to the root problem. This often comes back to soil organic matter and its management, but not always. Even if you have figured out that higher organic matter is the solution, you know WHY this is the problem and what other problems are related to it. This is an improvement on just building soil organic matter for the nebulous goals of soil health or soil biology.

Now that you have identified the root problem you can attack the problem directly rather than through “soil biology” or some similarly vague tool. This  problem-based soil evaluation will quickly focus your attention on the actual functions of your soil. It bypasses the fuzzy idea of achieving “soil health” and identifies something to guide your management decisions. It grounds your actions on solving a problem. Then it is much easier to decide what to do first and how to evaluate your progress.

What about soil health testing?

Having identified your problems, you can proceed with management and with soil health testing. “Test your soil” is a long-time mantra of Agricultural Extension, because, as the saying goes, you cannot manage what you don’t measure. But like testing your soil’s nutrient levels and then making decisions based on your planned crop, you can conduct soil health testing with a certain problem in mind. Perhaps there are tests that are associated with your problem more than others. Use those to evaluate your plan to address the problem.

Perhaps this is all just common sense, but common sense is needed here. This method is specific, practical, and immediately useful. It drives solutions that solve the problem in a way that soil testing by itself cannot. What if you don’t identify any problems or if you solve them? Do you then have a healthy soil? I think that, as with a healthy person, a healthy soil should not be expected to be completely free of problems – a healthy person is still susceptible to colds, or the flu – but overall a healthy soil will have fewer problems than an unhealthy one, and be able to overcome those problems that do occur.

Soil biology and soil organic matter; What do recent discoveries mean for soil management?

This Changes Everything.

That is how everything is presented in today’s media. New cars, new policies, new science. An example of the latter are the recent advances in the field of soil microbiology, or “soil biology” in pop-ag speak. Soil biology has become the means, the end, and the banner flying over the soil health movement. In particular, the recent focus on the vital role of soil microbes in the production of soil organic matter has become a “This changes everything!” call to arms.

Collage of "This Changes Everything" images generated by Google search
This Changes Everything is a common marketing slogan. Does it apply to the recent advances in soil microbiology? Screen shot of Google search.

I have been hesitant to completely embrace this “soil biology” revolution because of the hype associated with it, and because I am not a soil microbiologist. Back in grad school, I audited a soil microbiology class; I took the class but not for a grade. As an engineer becoming an agronomist, I knew I didn’t have the biology background to succeed in the class, but it was fascinating. Lost in the details, I tried to focus on the larger trends that were applicable to farming. I will again use this strategy here. While the new scientific discoveries are important, revealing the details of microscopic soil life with new clarity, do they change everything? Here is my agronomist take on what has changed, what hasn’t, and what it means for soil management.

Change 1: The microbial pathway to soil organic matter

This change brings soil microbes to the forefront in the formation of soil organic matter (SOM). Rather than just breaking down plant material until what is left is SOM or humus, soil microbes actually produce compounds that become SOM (Kallenbach et al., 2016). And when they die, microbe “necromass” can also become SOM. Perhaps 50% or more of the total SOM is formed through this microbial pathway (Kästner and Miltner, 2018).

Change 2: Stable humus concept questioned

The longtime view of humus as a component of SOM resistant to decomposition, and therefore stable and long-lived, is now in question (Lehmann and Kleber, 2015; Woolf and Lehmann, 2019). The alternative view is that humus is created by our extraction methods and that natural SOM is much more dynamic, with constant turnover from protected locations on clay and in aggregates being the norm (A WSU publication on the nature of SOM should be out later this year).

Change 3: The clay connection to soil organic matter

Recent observations suggest that microbial-derived SOM is most often attached to clay and smaller silt particles (Sokol et al., 2019). The bonding of SOM to clay protects the SOM from microbial decomposition, at least for a while. This SOM is called mineral associated organic matter (MAOM).

SOM is also protected within soil aggregates. But these protections are shorter-lived than we had thought, and even protected pools of SOM are constantly being decomposed and replaced (Woolf and Lehmann, 2019).

Change 4: Roots and root exudates are important

Root biomass and exudates are much more likely, up to 5x by some estimates, (Jackson et al., 2017; Sokol et al., 2018) to become SOM than aboveground plant biomass, mainly because of their location; they are already in the soil in contact with all the microbes just waiting to process them when they die. Furthermore, roots deep in the soil profile are subject to lower decomposition rates than surface roots or surface applied biomass.

Many root exudates are produced by plants for microbes in the soil rhizosphere. Exudates are then rapidly used by microbes in the rhizosphere and so are important for the microbial pathway to SOM. In exchange, microbes supply nutrients, water in some cases, and provide other advantages to plants such as helping them resist plant pathogens. Root exudates and the associated processes are difficult to study (Oburger and Jones, 2018), and complicated. For this reason, exudates are often studied in the lab rather than the field.

What has not changed?

While this new knowledge is important to our understanding of soils, I find the implications of these discoveries on management of soil are overstated, generally not by researchers, but by the popular press and others promoting soil health. They reason that since we have not been able to study soil biology very well until recently, by studying it now with the new tools and guided by new knowledge, all will change.

Here are some things that have not changed.

Plant biomass is still the driver of SOM formation

Just like us, microbes live, either directly or indirectly, on the energy in plant inputs. Plant biomass, produced through photosynthesis, is the raw material and microbes are the processors that transform the material into SOM.

“Plant input fuels the whole system and drives the microbial pump.” Kastner and Miltner 2018

Microbes do not produce all SOM; some SOM is still decomposed plant material, often in sand-sized particles, called particulate organic matter. This type of SOM is more important in low-clay soils because they don’t have clay to protect SOM, but it can be protected in soil aggregates.

No matter the specific mechanisms leading to its formation, the level of SOM in a soil is still a result of SOM gains and losses (Caruso et al. 2018). So, it still holds that using practices to either reduce losses or increase gains of SOM will lead to higher SOM levels.

Increasing SOM levels is still slow and difficult

Regardless of the newly understood microbial and root biomass/exudate pathways to SOM formation, the low conversion rates of plant biomass to SOM, measured for many decades in many types of systems, both managed and unmanaged, still apply. This needs some explanation.

For a long while, we have measured plant biomass flows into the soil, and losses of CO2 from the soil and the resulting levels of soil organic matter without knowing the details of the processes involved. This has been done in managed systems like farms, and in wild ecosystems. Between the measured inputs and the resulting SOM levels was a black box. We did not have the tools to see inside it: most of the components are microscopic; our intrusive methods changed the box’s environment; and most of the life in the box could not be cultured in a lab. We could only guess at what was happening there. Some say we ignored the biology because we were too focused on the chemistry, it being much easier to measure and change. There was some of that, but the lack of tools for identifying and quantifying soil microbes was the biggest factor in keeping the box black closed.

Schematic showing measurable inputs and outputs w/ a black box between them.
Researchers have been measuring inputs to the soil and outputs, the change in soil organic matter levels, for a long time. It is only recently that they have begun to figure out the details of what happens in the black box between.

Nevertheless, researchers made many of these measurements. From them we know that increasing the total amount of organic matter in a soil is not an efficient process; it takes a lot of plant biomass to produce a little soil organic matter. Most of the plant biomass is lost in the black box, used as an energy source by microbes, with the carbon leaving as CO2 and the nutrients being recycled in the microbial biomass.

It varies by input and how it is handled, but only 3-33% of plant material ends up as soil organic matter. (Castellano et al. 2015 review). The conversion rates for pre-digested soil amendments like compost or manure are better. Wuest and Gollany 2013 found that 24-39% of manure or compost became SOM. Other studies give similar results, even those specifically looking at the role of the soil biology. In one of the first papers to show that microbes can directly produce SOM, Kallenbach et al. (2016) still found that only 25% of the added plant materials, in this case glucose, dissolved organic carbon, cellobiose, and lignin, became SOM.

Whatever the input, changing SOM levels requires lots of plant biomass which in practical terms translates to slow change over time unless biomass is imported as with manure and compost.

Roots and root exudates have always been there

What about our imperfect measurements of the inputs, like roots and root exudates? It is true that often only aboveground biomass is measured for calculating the conversion rates. Roots are difficult to measure, and even when we try, the results are questionable (Bolinder et al., 2002). Root exudates are even more difficult because their production varies by plant, time of year, soil conditions, and because they are very short-lived being almost immediately taken up by microbes in the rhizosphere (Oburger and Jones, 2018).

In contrast, our measurements of total SOM have been reasonably reliable over time. Scientists continue to debate the nature of soil organic matter, where it is stored in the soil, the duration of various pools of SOM, but in general, we know how to measure it as a whole. The measurements have not changed much over time and if one picks one of the accepted methods and sticks with it (Roper et al., 2019), the data is reliable.

What happens when we include roots and root exudates in the calculations of the conversion rate? The conversion rate is the change in SOM divided by the inputs. ΔSOM/shoots+roots+exudates. Using some recent estimates of root and exudate biomass quantities in the calculations, we find that our conversion rates decrease not increase:

SOM/shoot biomass = 20/100 = 20%SOM/Shoot + Root biomass = 20/200 = 10%SOM/Shoot + Root + Exudate biomass = 20/260 = 7.7%

 

This example shows why, in general, our knowledge that microbes are an essential part of the SOM formation does not change everything. Even when we did not know about this process, it was happening. Even when we ignored the inputs from roots and didn’t know about root exudates, they were always there contributing to the process. Even when we incorrectly attributed the entire process to something different than what it was, the process continued just as it does today. Making SOM is no easier just because we know that soil microbes are doing much of the SOM formation and that roots and their exudates are key inputs.

How might this change soil management?

Instead of changing everything and rendering older research obsolete, this new knowledge can explain observations that we have been making for decades.

It explains why perennials, especially grasses, are better at building SOM. Not only because the soil is undisturbed in perennial systems, but because perennial grasses divert more of their available photosynthate to roots and root exudates, and because they are alive all year long (King and Blesh, 2018).

It explains why legumes are particularly good for soils. They are better than non-legumes at building SOM because of their high N content (low C:N ratio) (Kallenbach et al. 2015), making them easy to decompose and so increasing soil microbial populations, which lead to higher conversion rates and higher SOM levels. See also Castellano et al. (2015) and Cotrufo et al. (2013).

It explains why higher clay soils can store more SOM than sandy soils. The microbial-produced SOM is preferentially stored on clay particles. The more clay you have in your soil, the more you can build this type of SOM (mineral associated organic matter).

Improving current and informing new practices

Just because these discoveries don’t change everything doesn’t mean they can’t help us improve farm practices. Here are a few possible ways that this new knowledge could guide us in tweaking the practices already known to build SOM levels.

Focus on producing more microbes

One potential strategy is to focus on producing microbes to increase SOM. This works best on soils with moderate to high clay levels. Higher quality plant materials such as legumes, or other high N, high nutrient status cover crops, might be better at building SOM because they are more easily broken down by microbes, resulting in a better conversion rate to SOM. Green manures may also fit in this strategy. These well-fertilized crops break down quickly, and even with the tillage involved in incorporating them, still end up increasing SOM if they are used regularly (McGuire 2012). One tradeoff here is that hard-to-decompose plant materials, high lignin materials, and high C:N materials, are valuable for protecting the soil surface from erosion.

Maintain continuous living roots

This is not new; it is a common soil health principle. It is what we have had for centuries in unmanaged grasslands and in managed pastures. The strategy can help in annual cropping systems, but there are tradeoffs unless livestock grazing is included as with many regenerative agriculture systems.

Produce more roots and exudates

This is where the science vs. what farmers are trying/claiming gets dicier. One idea is to limit or eliminate fertilizer and other nutrient inputs (manure, compost) to force plants to work to get their nutrients from the soil. And by working, I mean produce more root exudates to feed the rhizosphere microbial community which then grows and produces more SOM. In exchange for the root exudates, plants get nutrients made available to them by the microbes. Mycorrhizal fungi are said to be the key player here, but other microbes are involved as well. Regardless of what the science says about whether this works or not, the clear tradeoffs are important to recognize.

Roots and exudates are produced at the expense of shoot production. There is no win-win as the amount of photosynthate is limited; a gain in one place means a loss in another. We harvest mostly shoots, so this would be a tradeoff in annual crops. We can manage or breed crops to produce more roots and exudates, but then we will have less aboveground crop to harvest. This is why, even in unmanaged natural ecosystems, plants will often respond positively to inputs of nitrogen or phosphorus.

Given the tradeoff, this root-exudate strategy would seem to work best in cover crops, but even with them there are tradeoffs. Less aboveground biomass in cover crops has been shown many times to result in more weeds, less soil protection, less nutrient scavenging, etc.

Focus on stable flow of carbon through soil

Another strategy was presented as a hypothesis by Dr. Markus Kleber, at a Potato Soil Health symposium in December of 2018. Kleber is an Oregon State University soil scientist who knows more about soil organic matter than I ever will. He speculated that we may find carbon flow through a soil may be more important than the level of stable carbon – soil organic matter – in that soil. He bases this on the new view that organic matter can be protected in the soil, but “is never inherently stable.” Microbes are just too good at breaking down organic materials for it to be around long unless otherwise protected.

The question Kleber raises was proposed by Janzen in his 2006 paper, The soil carbon dilemma; Shall we hoard it or use it? When the focus was on stable humus, “hoard it” was the goal. Now, Kleber believes, we may be swinging towards the “use it” tactic. After all, it is the flow of carbon through the soil, from plant to microbe to SOM to CO2 and back again that drives the biological processes. Janzen (2015) concludes in a later paper “…managing carbon flows should take precedence over maximizing carbon stocks.”

Kleber does not discount SOM, “Increasing organic matter content is almost always beneficial to the soil, especially when soils start out low in carbon” but wonders if the goal should be increased flow instead of increased storage. In support of his hypothesis he offered preliminary results from a potato study that found the total SOM levels did not differ between fields with high and low levels of a soilborne pathogen, but soil respiration – a measure of the microbial activity and therefor, of carbon flow – did differ.

He calls for “maintaining a steady supply of carbon” rather than a high or low supply.

This could be connected to the continuous living roots principle; not as concerned with building SOM but rather keeping the C moving through the soil. Cover crops and organic soil amendments would also work for this strategy. The only difficult part is measuring the flow. Perhaps analyses that aim to measure the active carbon portion of SOM, done at the same time of the year, and then compared over the years would help. Active carbon is the part of soil organic matter most available for consumption by soil microbes. An increasing number of commercial soil labs are offering to test for active carbon using the permanganate-oxidizable carbon test or POXC. I am collecting POXC data on a wide range of soils in irrigated Eastern Washington as part of a project funded by the WA Soil Health Committee. Combined with a measurement of carbon mineralization like soil respiration, it is an idea worthy of testing by farmers and researchers.

Detailed description of table linked in image
Soil scientist Markus Kleber thinks that carbon flow may be as or more important than soil organic matter levels. Here is what he proposes we would want in an ideal input to maintain C flow. Used with permission.

Kleber has several ideas of how to keep this steady supply of C to the soil. First, using liquid manure or other organic wastes spoon-fed through center pivot irrigation systems like fertigated nutrients. What may be more feasible for most farmers are roots, root mucilage, and root exudates, as we have covered, through the use of cover crops, which he calls “a technology to supply soil with active carbon.”

Details vs. the Big Picture

That is my take on the big-picture, agronomic view of recent advances in soil science and how they relate to practices in the field. However, when you start looking at the details of an immensely complex environment like the soil, you are bound to find some contradictions. For instance, highly biodegradable materials do not always convert better to SOM (Kallenbach et al. 2019). Science is slow, especially ag field research which can take years or decades to get clear answers to some questions. Compared to farmers for whom every crop is a risky entrepreneurial startup, science is a risk-averse, deliberate method. So, it will take a while to either confirm these ideas or test new ones. In the meantime, there ARE proven benefits of keeping the soil covered (by living plants when possible), cover crops, perennial crops, etc. The real questions are in the details of how far these time-proven practices can take us in improving and managing our soils.

References

Bolinder, M.A., D.A. Angers, G. Bélanger, R. Michaud, and M.R. Laverdière. 2002. Root biomass and shoot to root ratios of perennial forage crops in eastern Canada. Can. J. Plant Sci. 82(4): 731–737. doi: 10.4141/P01-139.

Castellano, M.J., K.E. Mueller, D.C. Olk, J.E. Sawyer, and J. Six. 2015. Integrating plant litter quality, soil organic matter stabilization, and the carbon saturation concept. Glob Change Biol 21(9): 3200–3209. doi: 10.1111/gcb.12982.

Cotrufo, M.F., M.D. Wallenstein, C.M. Boot, K. Denef, and E. Paul. 2013. The Microbial Efficiency-Matrix Stabilization (MEMS) framework integrates plant litter decomposition with soil organic matter stabilization: do labile plant inputs form stable soil organic matter? Global Change Biology 19(4): 988–995. doi: 10.1111/gcb.12113.

Guenay, Y., A. Ebeling, K. Steinauer, W.W. Weisser, and N. Eisenhauer. 2013. Transgressive overyielding of soil microbial biomass in a grassland plant diversity gradient. Soil Biology and Biochemistry 60: 122–124. doi: 10.1016/j.soilbio.2013.01.015.

Jackson, R.B., K. Lajtha, S.E. Crow, G. Hugelius, M.G. Kramer, et al. 2017. The Ecology of Soil Carbon: Pools, Vulnerabilities, and Biotic and Abiotic Controls. Annu. Rev. Ecol. Evol. Syst. 48(1): 419–445. doi: 10.1146/annurev-ecolsys-112414-054234.

Janzen, H.H. 2006. The soil carbon dilemma: Shall we hoard it or use it? Soil Biology and Biochemistry 38(3): 419–424. doi: 10.1016/j.soilbio.2005.10.008.

Janzen, H.H. 2015. Beyond carbon sequestration: soil as conduit of solar energy. European Journal of Soil Science 66(1): 19–32. doi: 10.1111/ejss.12194.

Kallenbach, C.M., A.S. Grandy, S.D. Frey, and A.F. Diefendorf. 2015. Microbial physiology and necromass regulate agricultural soil carbon accumulation. Soil Biology and Biochemistry 91: 279–290. doi: 10.1016/j.soilbio.2015.09.005.

Kallenbach, C.M., S.D. Frey, and A.S. Grandy. 2016. Direct evidence for microbial-derived soil organic matter formation and its ecophysiological controls. Nature Communications 7: 13630. doi: 10.1038/ncomms13630.

Kallenbach, C.M., M.D. Wallenstein, M.E. Schipanksi, and A.S. Grandy. 2019. Managing Agroecosystems for Soil Microbial Carbon Use Efficiency: Ecological Unknowns, Potential Outcomes, and a Path Forward. Front. Microbiol. 10. doi: 10.3389/fmicb.2019.01146.

Kästner, M., and A. Miltner. 2018. SOM and Microbes—What Is Left From Microbial Life. In: Garcia, C., Nannipieri, P., and Hernandez, T., editors, The Future of Soil Carbon. Academic Press. p. 125–163

King, A.E., and J. Blesh. 2018. Crop rotations for increased soil carbon: perenniality as a guiding principle. Ecological Applications 28(1): 249–261. doi: 10.1002/eap.1648.

Lehmann, J., and M. Kleber. 2015. The contentious nature of soil organic matter. Nature 528(7580): 60–68. doi: 10.1038/nature16069.

McGuire, A.M. 2012. Mustard Green Manure Use in Eastern Washington State. In: He, Z., Larkin, R., and Honeycutt, W., editors, Sustainable Potato Production: Global Case Studies. Springer Netherlands. p. 117–130

Oburger, E., and D.L. Jones. 2018. Sampling root exudates – Mission impossible? Rhizosphere 6: 116–133. doi: 10.1016/j.rhisph.2018.06.004.

Roper, W.R., W.P. Robarge, D.L. Osmond, and J.L. Heitman. 2019. Comparing Four Methods of Measuring Soil Organic Matter in North Carolina Soils. Soil Science Society of America Journal 83(2): 466–474. doi: 10.2136/sssaj2018.03.0105.

Sokol, N.W., Sara.E. Kuebbing, E. Karlsen-Ayala, and M.A. Bradford. 2018. Evidence for the primacy of living root inputs, not root or shoot litter, in forming soil organic carbon. New Phytologist 0(0). doi: 10.1111/nph.15361.

Sokol, N.W., J. Sanderman, and M.A. Bradford. 2019. Pathways of mineral-associated soil organic matter formation: Integrating the role of plant carbon source, chemistry, and point of entry. Global Change Biology 25(1): 12–24. doi: 10.1111/gcb.14482.

Woolf, D., and J. Lehmann. 2019. Microbial models with minimal mineral protection can explain long-term soil organic carbon persistence. Scientific Reports 9(1): 6522. doi: 10.1038/s41598-019-43026-8.

Wuest, S.B., and H.T. Gollany. 2013. Soil Organic Carbon and Nitrogen After Application of Nine Organic Amendments. Soil Science Society of America Journal 77(1): 237–245. doi: 10.2136/sssaj2012.0184.

Rapid Evaluation of Winter Wheat Residue Decomposition Potential

In recent months several BIOAg-funded projects came to a close. This post is a summary of one of the finished projects. To read the full project report, please follow the link within the post.

Wheat residue on dry field
Wheat residue on field near Ritzville, Washington, which is part of the a grain-fallow cropping system. (Photo: D. Kilgore)

Managing crop residue is essential to reduced and no-till farming systems that enhance soil health and reduce soil erosion. And growers in different parts of the dryland Pacific Northwest are likely seeking different residue characteristics. In most areas with less than 12 inches of annual precipitation, wheat is grown every other year, and land is fallowed in between to conserve moisture. Having a cultivar which has a slow straw breakdown would help reduce soil erosion by wind and retain more of the scarce water in the soil. In contrast, where annual rainfall exceeds 18 inches, wheat yield, and residue production, is much higher. As a result, when growers try to direct seed into the winter wheat stubble in the spring, it can oftentimes be difficult due to the high amount of remaining residue.

Growers in these areas are searching for cultivars with residue that decomposes quickly. Growers, and the seed dealers they work with, regularly request information on residue decomposition of  winter wheat cultivars, but none is currently available. Arron Carter and colleagues’ 2017 project, “Rapid Evaluation of Winter Wheat Residue Decomposition Potential,” aims to develop efficient methods to provide this information – and lay the groundwork for future breeding efforts that select for wheat varieties with the decomposition characteristics that growers want. The project explored the degradability characteristics of wheat, and how degradability might be dependent on both genetic and environmental factors. It also sought to identify regions of the wheat genome involved in degradability, and to develop new, faster methods for evaluating degradability.

Under the BIOAg project, the team analyzed a set of 151 lines created by crossing two varieties with very different decomposition characteristics (Eltan and Finch). Based on these preliminary results, Carter and his students successfully approached Western SARE to support additional work – as results from the BIOAg project indicated that repeating the work with a population that had more genetic diversity would generate more conclusive insights. They are now repeating the work with a large diversity panel of 480 soft white winter wheat lines from the Pacific Northwest that represents maximized allelic and phenotypic diversity.

The results from these studies indicated that both genetic and environmental factors are important for determining degradability – but not all lines respond to the environment in the same way. Thus recommendations for growers in one location who want a degradable wheat residue are likely to be different than recommendations for growers in another location who want a degradable wheat residue. Using the results the team acquired from the diversity panel, which includes a large number of wheat varieties currently being grown, Carter is now able to give recommendations to growers across the region about varieties they should consider based on their residue needs. He has also discovered that this information is of interest to researchers working on other types of more sustainable systems across the region – for example, those seeking to develop approaches for using wheat straw to produce cellulosic ethanol.

Carter and his team have identified about 20 genomic regions associated with the degradability traits. Each of these genetic regions contributes to a small amount of the variation – indicating that the factors that contribute to degradability are likely to be complex. It also means that selecting for any single one of these genetic regions in breeding is unlikely to have much impact on degradability – though focusing on a set of multiple regions (for example, 6-8 or more regions) could be beneficial. The team is still working with the larger diversity panel to see if they can identify additional genetic regions that are important. In the process, they hope they will continue to develop a better understanding of the genetic factors that contribute to degradability, with the hope of better informing breeding efforts.

Last, the team is working to develop new methods that rely on near-infrared (NIR) spectroscopy for evaluating degradability – methods that would be much faster than the wet chemistry methods currently used. The NIR prediction models generated from their BIOAg data were moderately correlated to trait values, and they are hoping to improve the model once they have finished evaluating the diversity panel.

The BIOAg project supported two graduate students, Alejandra Roa and Nathan Nielsen. Building on the work under BIOAg, USDA-NIFA and the Washington Wheat Commission have awarded funds to make NIR testing standard within the WSU winter wheat breeding program. The OA Vogel and Willard Hennings Endowment, and Western SARE, have supported continuation of this work. The full grant report PDF is available online.

Using Natural Defense Responses to Protect Against Pest Damage in Potatoes

In recent months several BIOAg-funded projects came to a close. This post is a summary of one of the finished projects. To read the full project report, please follow the link within the post.

Peptide elicitors are naturally occurring signaling compounds that act within plants to induce and amplify defense responses. If specific peptide elicitors could be identified and synthesized, they could be used to maximize plants’ natural immunity, providing a more sustainable approach to controlling disease caused by pathogens and pests. Peptide elicitors do not interact directly with pests, so pests are not expected to develop resistance. As natural compounds, peptide elicitors are unlikely to have negative side effects on human or environmental health.

petri dish on left with white root hairs visible; microscopic image on right showing black dots throughout
Figure 1. A hairy root culture system and Sss infection. Left shows a hairy root culture in petri dish. Right picture shows microscopic image (200x magnification) of the root tissues infected by Sss. The picture was taken 6-8 weeks after application of purified Sss cystosori (2 x 104).

Making this potential tool a reality requires crop-specific scientific work to identify peptides that induce strong defense responses. Kiwamu Tanaka, Lee Hadwiger, and others have been laying the groundwork for the use of peptide elicitors in potato using a powdery scab disease caused by a protist pathogen, Spongospora subterranea f. sp. subterranea (Sss). Typically, powdery scab can only be studied under field conditions. Within their BIOAg project, the team developed a hairy root culture that could be used as a lab-based powdery scab infection system, and confirmed that the system can be used for rapid, scalable, high-throughput screening of peptide elicitors against powdery scab infection under controlled conditions (Figure 1).

Then Tanaka and collaborators turned their attention to identifying new peptide elicitors that evoked a stronger, and more specific response against powdery scab than STPep1, a known peptide elicitor. Multiple fractions containing active compounds were extracted and purified from infected potato cells. Each fraction was then applied to the hairy root culture system, and researchers monitored early defense response using an extracellular alkalinization assay previously developed by the team. The most active fractions contained roughly 17,000 different possible candidate peptides. Narrowing candidates to those peptides that were derived from potato and enriched in powdery scab-infected samples led to about 100 peptides that are finalist candidates. The team is proceeding to test each of these candidates for defense-inducing activity.

This BIOAg project funded one WSU Masters student, and involved two high school interns from Hunters, WA and Yakima, WA. Work completed through the BIOAg project has been leveraged to obtain additional funding from the Northwest Potato Research Consortium and USDA AFRI that will continue the work. Two scientific publications are being prepared. The full project report (PDF) is available online.

The Devil is in the Process: Co-composting Biochar Could Benefit Crop Growth and the Environment

Biochar has the potential to sequester carbon and improve the properties of soils when used as an agricultural amendment. However, biochar will only be a viable option for carbon sequestration if there are uses and viable markets for this biochar. In recent years, there has been interest in adding biochar to agricultural soils in conjunction with compost, and in some cases, “co-composting” biochar—putting the biochar in with the feedstock before the composting altogether. Read on to learn about a study led by Dr. David Gang, a professor at Washington State University’s Institute of Biological Chemistry, indicating that co-composting can provide additional benefits, both during the composting process and to the crops grown in soil amended with the resulting co-composted biochar.

The co-composted biochar used in this study was made using a set proportion of screened dairy manure solids and bedding straw, woody yard waste, and food scraps. Some of the compost piles also contained 2.5% or 5% (by volume) biochar. Even before adding the compost to the soil there were benefits: the addition of biochar to the feedstocks led to significant reductions in the volatile organic compounds measured during the composting process, which can make compost smell bad (Figure 1).

3 men watching equipment on the ground
Figure 1. Mark Fuchs (L), John Cleary (R) (both of the Washington Department of Ecology) and Nathan Stacey (middle, WSU) use equipment to measure gas emissions from a commercial scale co-composting experiment. (Photo credit: Doug Collins, WSU).

While sweet basil is not considered one of the Pacific Northwest’s major commodity crops, it is a high value crop that is frequently grown under organic conditions, making it well suited to receive high-value organic amendments, such as compost and biochar. Gang and collaborators tested the co-compost by blending it as part of a soil mixture and using it to grow two different cultivars of sweet basil (Eleanora and TSQ) in pots in a greenhouse.

Interestingly, neither compost alone, nor compost with biochar added when applied to the soil, made a difference to the growth of the sweet basil plants. Co-composting the biochar (at 2.5% or 5%), however, caused a significant increase in plant fresh weight relative to treatments receiving a combination of biochar and compost (Figure 2).  This result suggests that something occurred during the co-composting process that affected the co-compost’s ability to promote plant growth.

biochar co-compost significantly different from others
Figure 2: Impact of biochar co-composting on biomass/yield of sweet basil cultivar Eleanora (a Genovese type of basil). Different letters indicate significant differences between treatments. (Source: Gang et al. 2018)

Sometimes getting bigger plants can be counter-productive, because the quality can be diluted. Gang and colleagues also measured the effects of the biochar and co-compost treatments on levels of the antioxidants and volatile compounds that create the characteristic flavor of basil. They found very little impact on either antioxidant levels or the production of flavor compounds in sweet basil, per gram fresh weight. This is a very positive result, showing that the higher yields did not result in decreased quality.

The mechanism by which co-composted biochar increased plant growth has yet to be fully understood, but the study authors suggest that these effects may be due to positive impacts on soil health, particularly composition and activity levels of the microbial community. That is, qualities of the co-composted biochar may have helped create a better environment in the soil for microbes that provided benefits to the basil plants.

The only potential downside to using biochar in co-composting is the potential for additional cost associated with the energy for producing biochar. However, biochar cost can be minimized if the energy for its production can be derived from the source materials, and if it and can be produced relatively locally, minimizing transportation costs. Even if there is some cost associated with biochar for co-composting, Gang is optimistic about the potential to offset it by the downstream benefits on crop yield.

While positive effects of soil amendments such as biochar and co-composted biochar are dependent on the specific combination of biochar, soil conditions, and crop cultivar, this study raises some interesting questions and the potential for a win-win situation, with benefits seen both during the composting process and for crops grown using the resulting product. If these play out as hoped and the costs of adding biochar are indeed outweighed by the benefits, compost facilities could be in the market for biochar, leading to greater capturing of carbon in this product, in agricultural soils. Gang’s team, working with a number of other collaborators, are currently following up on these intriguing results to test the impacts of biochar co-compost on gas emissions, co-compost quality, and crop yield and quality of sweet basil, strawberries, and potatoes, both in the greenhouse and in the field (Figure 3).

field plots
Figure 3. Co-composted biochar spread on experimental field plots before tillage and planting of potatoes. (Photo credit: Doug Collins, WSU)

For more information on this project and others funded through the Waste to Fuels Partnership, please see the Waste to Fuels Technology Partnership 2015-2017 Biennium Report.

This work was funded through the Waste to Fuels Technology Partnership between the Center for Sustaining Agriculture and Natural Resources at Washington State University and the Washington Department of Ecology’s Solid Waste Management Program (previously Waste 2 Resources Program). This partnership advances targeted applied research and extension on emerging technologies for managing residual organic matter.

 

Reference:

Gang, D.R., A. Berim, R. Long, J. Cleary, M. Fuchs, R.W. Finch, M. Garcia-Perez, and B.T. Jobson.  2018.Evaluation of Impact of Biochar-Amended Compost on Organic Herb Yield and Quality. Chapter 10 in Chen, S. et. al. 2018. Advancing Organics Management in Washington State: The Waste to Fuels Technology Partnership. Waste 2 Resources, Washington State Department of Ecology Publication No. 18-07-010. Olympia, Washington. https://fortress.wa.gov/ecy/publications/SummaryPages/1807010.html

 

This article is also posted on https://www.agclimate.net/ 

Could Wood Plastic Composites Motivate More Investments in Climate-Friendly Anaerobic Digestion?

 

Picture this future scenario: it’s a hot summer day and you are sitting with some friends on their deck enjoying a cold beverage. You notice they recently replaced their deck and, interested, you ask about the decking material they used, only to find out that it’s made partially out of . . . manure from dairy cows! Surprised? Work done by researchers at Washington State University investigated this potential method for adding value to an agricultural waste product.

Anaerobic digestion (AD) of dairy manure has potential to generate renewable energy, improve the bottom line for dairy farmers, and turn dairies from a net source to a net sink of greenhouse gases (Kruger and Frear 2010; Figure 1). A previous post explored the expense of AD technology and an article from the Ag Climate network blog discussed the benefits of AD. The economics of AD depend on a number of factors, including whether a use—and a market—exists for the large quantities of digested fiber that remain after the process. Typically, this fiber is either reused as bedding either on-farm or elsewhere, or composted for use as a soil amendment. Other methods for adding value to AD fiber include using it as a feedstock for biochar (Ayiania 2019) or as a substitute for peat moss in container plant systems (Palaez-Samaniego et al. 2017). Use of AD fiber as a peat moss substitute has even reached a commercial level. Research from the lab of Dr. Manuel Garcia-Pérez at Washington State University examined yet another potential use for this fibrous product: as an ingredient in wood plastic composites.

cows in barn
Figure 1: Anaerobic digestion has the potential to turn dairies from a source to a sink of greenhouse gases, but capturing value from co-products is critical for economic viability of anaerobic digestion. Photo: Darrell Kilgore, CAHNRS Communications.

The particle size and geometry of fibers from digested dairy manure make it a suitable substitute fiber for engineered wood products, specifically products called wood plastic composites (WPCs), which are widely used for decking and have experienced market growth in recent years. One factor limiting use of WPCs in wet places like Seattle or Portland is their tendency to absorb water, which reduces their strength. Somewhat ironically, steeping the fiber in hot water (called hot water extraction), changes its composition and improves moisture resistance. The question is, will this translate to beneficial changes in the properties of the WPCs?

Gabriela Pereira-Ferraz, a former graduate student in Dr. Garcia-Pérez’s research group, compared samples of WPC made from Eastern white pine wood “flour” (a standard fiber used in WPCs) to those made from AD fiber, in its original form, and AD fiber treated by hot water extraction. The researchers created sample boards from each of the fibers and investigated specific mechanical properties of the WPCs that are important for their functionality, strength, and water resistance.

After the AD fiber was treated with hot water extraction it lost 21% of its mass, and researchers observed changes in its surface structure, which became rougher (Figure 2). The structural changes resulting from hot water extraction led to improvements in mechanical properties and water resistance of the resulting WPC material.  To test water uptake, samples of the WPCs were immersed in water. Treating the AD fiber reduced moisture uptake by 39.1%, and swelling by 36.0%, after 127 days of water immersion. Though decking material would not typically be immersed in water for 127 days, this type of laboratory testing exposes materials to conditions more extreme than what they might experience while in use. The 39.1% reduction in moisture uptake, for example, does not necessarily translate to water uptake by these materials if used on your deck, rather the results of laboratory tests allow researchers to compare the properties of different materials.

Another property measured was “strain at break,” a measure of how much strain is applied to the material in a controlled laboratory setting before the material breaks. Hot water treatment improved the strain at break measurement by 15%. On a practical level, this means that hot water extraction produced a stronger composite material than AD fiber that had not undergone hot water extraction. AD fiber that underwent hot water extraction was more water resistant than pine and performed as well or better than pine fiber for three of four mechanical properties measured.

two images of material with large holes. Left image appears smoother.
Figure 2: Scanning electron microscopy images of untreated anaerobic digester (AD) fiber (left) and 160°C hot water extracted (HWE) AD fiber (right) (20,000×). The image on the right shows rougher fiber with coalesced droplets of lignin-rich material, due to hot water extraction. Photo source: Pereira-Ferraz et al., 2017.

These laboratory results are promising. However, in order to move this end-use for AD fiber to commercialization, more work needs to be done to evaluate the economics of scaling up the process. Wood plastic composites may offer another way to add value to fiber from anaerobic digestion of dairy manure, further improving the economics of these systems. Increased use of anaerobic digestion for dairy manure would be a net benefit from a climate change perspective. Developing feedstock for WPCs from AD fiber would therefore be good for both the climate and for the dairy farmer’s bottom line.

For more information on this project and others funded with Biomass Research Funds from the Washington State University Agricultural Research Center, please see the report: Technology Research and Extension Related to Anaerobic Digestion of Dairy Manure 2015-2017 Biennium PDF.

Results of this work have been published as:

Pereira-Ferraz, G., Frear, C., Pelaez-Samaniego, M.R., Englund, K. and García-Pérez, M. 2016. Hot Water Extraction of Anaerobic Digested Dairy Fiber for Manufacturing Wood Plastic Composites. Bioresources 11 (4): 8139-8154.

Pereira-Ferraz, G., Frear, C., Pelaez-Samaniego, M.R., Englund, K., and García-Pérez, M. Production of Composite Materials from Anaerobic Digestion Fiber. 2017. Chapter 7 in: Technology Research and Extension Related to Anaerobic Digestion of Dairy Manure 2015-2017 Biennium PDF. 2017. Compiled and edited by Hills, K., Hall, S.A., Saari, B., Zimmerman T. A Project Report for the Washington State University Agricultural Research Center and the Washington State Department of Agriculture. 173 pp.

 

References:

Ayiania, M., Carbajal-Gamarra, F.M., Garcia Perez, T., Frear, C., Suliman, W., and Garcia Perez, M. 2019. Production and characterization of H2S and PO43- carbonaceous adsorbents from anaerobic digested fibers. Biomass and Bioenergy 120:339-349.

Kruger, C.E., Frear, C. 2010. Lessons Learned About Anaerobic Digestion (Chapter 12). In Kruger, C., G. Yorgey, S. Chen, H. Collins, C. Feise, C. Frear, D. Granatstein, S. Higgins, D. Huggins, C. MacConnell, K. Painter, C. Stöckle. Climate Friendly Farming: Improving the Carbon Footprint of Agriculture in the Pacific Northwest. CSANR Research Report 2010-001. Washington State University: http://csanr.wsu.edu/pages/Climate-Friendly-Farming-Final-Report/.

Palaez-Samaniego, M.R., Humel, R.L., Liao, W., Ma, J., Jensen, J., Kruger, C., and Frear, C. 2017. Approaches for adding value to anaerobically digested dairy fiber. Renewable and Sustainable Energy Reviews 72:254–268.

This article is also posted on https://www.agclimate.net/ 

My Tilth Conference up close

This year CSANR sponsored travel for several WSU students to attend the Tilth Conference in Spokane, WA. We are posting reflections written by the students over the next several weeks. Please feel free to comment and give these students your feedback.  To view student posts from this year and prior years, visit http://csanr.wsu.edu/tag/tilth/

Cody's headshot
Cody Holland

First, I would like to thank CSANR for generously funding my, and my classmates’, attendance at TILTH Conference 2018. Especially for undergraduates like myself, conferences such as TILTH are a welcome departure from the oftentimes synthetic academic track, onto a more organic (no pun intended) professional one.

The Friday farm tour (or, more aptly, warehouse, ranch, and farm tour) was right up my alley, i.e., right where the magic happens, talking to the proverbial “man behind the curtain.” Last spring term, I took my capstone course (AFS 401) which was replete with field experiences just like these—touring chickpea processing facilities, farm shops, WSCIA meetings. I learned things a mile-a-minute. It was the same at the TILTH Farm Tour, thanks to Beth Robinette (LINC Foods & Lazy R Ranch), Maurice Robinette (Lazy R Ranch) and Patrick Mannhard and Tarawyn Waters (Urban Eden Farm). Being a Spokanite, all three of these establishments were on my radar—I had even volunteered twice at Urban Eden Farm—but setting foot inside LINC’s central-Spokane warehouse and the Robinette’s ranchland was revelatory. The LINC warehouse, and Beth’s narrative, made sense—this was no small thing. In short, LINC Foods is a worker, farmer—and, see fine print—investor owned cooperative food hub that deals regionally in fruit & vegetable produce, animal products, and grain products (including a burgeoning malt op.)… AND, it’s working (pending projected profits in the upcoming fiscal year). Something frustratingly rife in the writ large discourse of sustainable food systems is cart-before-the-horse ideology. LINC (2/7ths of LINC, that is), Beth Robinette and Joel Williamson have defied this trend by (literally) doing their homework (each with MBAs) and taking a sober look at the business viability of LINC before financing the startup. The result? LINC Foods is realizing its mission of building a “regional, sustainable food system by linking local farmers to new markets and ensuring the highest quality products for our customers through democratic enterprise.” Food security, buttressing regional economy, progressive business structure.  Check, check and check.

Lazy R Ranch, in the same vain as LINC Foods, is equal parts sustainable and pragmatic. Not surprising, seeing as Lazy R is a Robinette family affair. Maurice Robinette practices holistic management on his beef cattle ranch, which as it happens, holds ecological and economic sustainability in equal regard. Much like LINC. Though Maurice is a producer, the sustainability of his ranch is not too dissimilar from Beth’s distributer sustainability. Profits are inextricable from the health of the whole system and vice versa.

Thank you, once again, to CSANR for sponsoring this growth experience. I hope to one day have a part in the eastern Washington sustainable food systems movement, as part of LINC Foods or another likeminded organization.

A multifaceted approach to tilth and the environment

This year CSANR sponsored travel for several WSU students to attend the Tilth Conference in Spokane, WA. We are posting reflections written by the students over the next several weeks. Please feel free to comment and give these students your feedback.  To view student posts from this year and prior years, visit http://csanr.wsu.edu/tag/tilth/

Matthew's headshot
Matthew Tumlinson

My name is Matthew Tumlinson, and I’m a junior undergraduate transfer student in my first semester at WSU. I’m working on my B.S. in Field Crop Management with a minor in Crop Science and working toward a certification in Organic and Sustainable Agriculture. I grew up mostly in Vancouver, Washington. I also lived in a pear growing region of northern California and a cherry growing region in Oregon for several years. However, during those times I had no knowledge of and little interest in agriculture; now I see those as opportunities missed. It was only during the last five years that I became interested in agriculture and the possibility of hobby farming for myself. My interest in agriculture mainly stems from a concern for the environment and a fascination for how plants work. Once I began to realize how connected agriculture and the environment were, I knew it was something I wanted to be a part of.

The 2018 Tilth Conference in Spokane, Washington was my first Tilth Conference experience. I was curious to see what the social climate surrounding Tilth was like and what was being done to raise awareness about the importance of soil health. I was looking forward to hearing about the overall vision for soil health in our area, as well as what resources are available to new or young farmers interested in getting started in agriculture with their soil’s health in mind. The conference sessions covered a range of topics from farm financing to sustainable farming practices. I walked away feeling inspired and impressed with the tireless work being done within Tilth Alliance to provide resources to farmers, students and the community; as well as with the variety of people in attendance and the different areas of expertise that were represented.

The guest speakers all gave insightful and interesting presentations and there was so much knowledge to absorb. One of the sessions that appealed to me was titled, “Finding Land to Farm, Finding a Farmer for Your Land”. The session had a panel of four speakers, Julie Kintzi of Cart Before Horse Farm; Chandler Briggs of Hayshaker Farm; and Jim Baird of Cloudview Farm. The session was moderated and contributed to by Amy Moreno-Sills of Four Elements Farm and PCC Farmland Trust. Julie and Amy both have off-farm jobs to support their small farms. Off the farm work will be necessary in my case, so I took some perspective and inspiration from that. I attended this session to learn about the hurdles of finding land and starting a farm, as well as balancing work life on and off the farm. They provided some very useful information about loan types and the Farm Link website for acquiring agricultural land. This was a session I was glad I attended.

The other session I thoroughly enjoyed was titled, “Using Native Bees to Increase Farm Yield,” presented by Dave Hunter of Crown Bees. Crown Bees has a great website that promotes native bees and carries supplies to help support these bees. I’ve been interested in beekeeping for a while and this session was big motivator for me. Dave talked about solitary bees and how they are different from bees belonging to colonies, and how efficient each are as pollinators. While all pollinators are generally good, Dave showed that some pollinators are having greater positive impacts than others on crop yields. There was much I didn’t know about bees which he discussed and there is much more that I’d like to learn about now. The session left me anxious to have land of my own and to be able to provide a habitat for pollinators in the future.

I would like to thank the Center for Sustaining Agriculture and Natural Resources (CSANR) for giving me the opportunity to attend the 2018 Tilth Conference. It was a great experience and one that I would highly recommend for any student interested in agricultural sustainability.

Understanding the Unbearable Whiteness of Farming

This year CSANR sponsored travel for several WSU students to attend the Tilth Conference in Spokane, WA. We are posting reflections written by the students over the next several weeks. Please feel free to comment and give these students your feedback.  To view student posts from this year and prior years, visit http://csanr.wsu.edu/tag/tilth/

 

Shannon's headshot
Shannon Brenner

As an aspiring farmer and a student of the social sciences, attending the Tilth conference provided a unique opportunity to engage with topics ranging from applications of sustainable agriculture to issues of gender and race in the organic farming world. Before coming to Washington State University for graduate school to study the sociology of food and agriculture, I was living and farming in Maine, attending the annual Maine Organic Farmers and Gardeners Association’s Farmer to Farmer Conference on several occasions. I was curious to see how the two organic farming conferences compared, in two states with strong organic and sustainable farming traditions.

I expected similar, high quality and intriguing talks on organic farming applications and techniques. At the Tilth Conference, I attended a talk on integrating pigs into a crop rotation system to improve soil quality, organic matter content, and nutrient composition. The presenter was highly engaging, innovate, and passionate, integrating clinical research and practical day to day operations on her farm in the same way I have seen the organic farmers in New England do.

However, I was pleasantly surprised and excited by the inclusion of talks under the track of Agriculture and Society at the Tilth Conference, a track I have not seen on programs at similar farming conferences. I attended two very meaningful sessions in this track, one on Women in Agriculture and another entitled The Unbearable Whiteness of Farming. Moderated by Audra Mulkern of the Female Farmer Project, the first panel of women farmers created a safe and inspiring space to talk about gender and farming; the labor, both physical and emotional, expected of women; and the importance of representation and mentorship for future female farmers.

It was the second session though, The Unbearable Whiteness of Farming, that was the most impactful. I could tell it was going to be a different kind of session from the moment I walked into the room. The lights were off, there was paper and pens on each table, and before any of the panel spoke, one of the women had us all stand in a circle to stretch and to make a land acknowledgement recognizing the Spokane tribal land upon which we stood. The four women of color on the panel did not have technical research to present, but rather spoke their truths about what it was like to farm as a person of color. And that is what made the session so powerful.

I do not feel it is my place to write those truths here, for they are not my stories to tell; however, I will say that I walked away from that session wishing it were a conference in and of itself. The thorny issues of white supremacy, colonialism, slavery, and reclaiming farming from all of it could not be adequately dealt with in the hour we had together. We need more time too examine that unbearable whiteness of farming to meaningfully address systems of power that maintain inequality and injustice. For example, there is a growing movement to address black land loss due to discriminatory government policy as well as a lack of access to capital and overall poverty (Center for Social Inclusion 2011). Though farmland has been decreasing across the board, black farmers are being disproportionately forced from their land with one out of seven farms being black-owned in 1920 down to just one out of 100 by 1992 (Kromm 2010).

Thus, I encourage all those involved in sustainable farming, in Tilth and beyond, to reflect on any privilege they may have, to think about connection to land and what that means when we think about race, power, and justice. We need all the farmers and farmland we can get, but we need to think about how to heal from past violence and move forward with honor, humility, and courage to do better.

Center for Social Inclusion. 2011. Regaining Ground: Cultivating Community Assets and Preserving Black Land.

Kromm, Chris. 2010. “The Real Story of Racism at the USDA.” The Nation.